1. Field of the Invention
The present invention relates to a backlight module, more particularly, to a driving circuit and a method for a light emitting diode (LED) backlight module.
2. Description of the Related Art
In recent years, with great advance in the fabricating techniques of opto-electronics and semiconductor devices, flat panel displays (FPDs) have been vigorously developed. Among the FPDs, a liquid crystal display (hereinafter “LCD”) has become the mainstream display product due to its advantages of outstanding space utilization efficiency, low power consumption, free radiation, and low electrical field interference.
In general, since an LCD panel does not emit light by itself. As such, it needs a backlight module disposed thereunder to provide plane light source required by the LCD panel. The conventional backlight modules could be classified two types. One of the two types is a backlight module composed by the cold cathode fluorescent lamps (CCFLs), and the other of the two types is a backlight module composed by the light emitting diodes (LEDs). Since the LED backlight module could promote the color gamut of the LCD, so that the current panel manufacturers mostly replace the CCFL backlight module with the LED backlight module.
However, since the LED backlight module nowadays is mostly driven by the pulse width modulation (PWM) and a concept of division controlling, so that when the number of areas/regions of division controlling are increased, it would be caused some following disadvantages:
1. The transmission lines and the transmission time would be substantially increased.
2. The control way of the PWM is not enough flexible.
3. Each area/region of division controlling would be disposed a current controller therein, so that the fabrication cost would be substantially increased.